Sub-app not working when mounted on "/"

I was trying to mount a sub-app on the root (“/”) but it was throwing an error:

/node_modules/polka/index.js:95
		let loop = _ => res.finished || (i < len) && arr[i++](req, res, next);
		                                                     ^

TypeError: arr[(i++)] is not a function

I tracked the error back to the .use() function of polka:

use(base, ...fns) {
		if (typeof base === 'function') {
			this.wares = this.wares.concat(base, fns);
                  // SUB-APP IS NOT HANDLED WELL BECAUSE OF THIS CONDITIONAL:
		} else if (base === '/') { 
			this.wares = this.wares.concat(fns);
		} else {
			base = lead(base);
			fns.forEach(fn => {
				if (fn instanceof Polka) {
					this.apps[base] = fn;
				} else { ... etc ....

I have been trying to find a temporary fix without succes. Or is there another way to go about this?

[lukeed]

Available with polka@1.0.0-next.7 via npm install polka@next 👍

[matthewrobb]

I, too, am having this same problem exactly.